linux-kernel - Re: [PATCH] lazy freeing of memory through MADV

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Date:	Mon, 23 Apr 2007 22:53:49 -0400
From:	Rik van Riel <riel@...hat.com>
To:	Nick Piggin <nickpiggin@...oo.com.au>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-mm <linux-mm@...ck.org>, shak <dshaks@...hat.com>,
	jakub@...hat.com, drepper@...hat.com
Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE

Nick Piggin wrote:

> What the tlb flush used to be able to assume is that the page
> has been removed from the pagetables when they are put in the
> tlb flush batch.

I think this is still the case, to a degree.  There should be
no harm in removing the TLB entries after the page table has
been unlocked, right?

Or is something like the attached really needed?

 From what I can see, the page table lock should be enough
synchronization between unmap_mapping_range, MADV_FREE and
MADV_DONTNEED.

I don't see why we need the attached, but in case you find
a good reason, here's my signed-off-by line for Andrew :)

Signed-off-by: Rik van Riel <riel@...hat.com>

-- 
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is.  Each group
calls the other unpatriotic.

View attachment "linux-2.6-madv_free-flushme.patch" of type "text/x-patch" (751 bytes)